Loops

for


for loop-variable := start to end do
looping-statement

for loop-variable := start to end by index do
looping-statement


The for loop initializes the loop variable to start. Each time through the loop, the loop variable is compared to end. If the loop variable is greater than end, the loop terminates. (If index is negative, it terminates when less than end.) Otherwise, the looping statement is executed and the loop variable is incremented by 1 (if index exists, the variable hops by index). Then, execution jumps back to the top, with a comparison to end.

The start and end expressions are evaluated exactly once. The looping statement is executed zero or more times. The loop variable is automatically created as a local variable (unless it is already local).

After the loop, the loop variable's value is undefined--don't rely on it.


An online version of Programming for the Newton using Macintosh, 2nd ed. ©1996, 1994, Julie McKeehan and Neil Rhodes.

Last modified: 1 DEC 1996